There are various types of breadcrumbs which have been requested by various consumers. These include American breadcrumbs that include a crust for both texture and coloring, Japanese breadcrumbs that have no crust and generally have a high rise during baking, and cracker meal crumbs which are more dense and baked to a more rigid consistency.
In the past it has been necessary for a manufacturer to have separate production lines for the various types of breadcrumbs requiring a duplication in invested capital and leading to idle time on one line or the other when there is a lack of demand for a particular type of breadcrumb.
Part of this is because American breadcrumbs are best produced by convection baking to help form the crust and require less baking time than Japanese breadcrumbs. Japanese breadcrumbs are not well suited to convection baking and are commonly baked by conduction heating or microwave heating to prevent the formation of crust. Furthermore, Japanese breadcrumbs require approximately double the oven time of American breadcrumbs.
More specifically, American breadcrumbs are made either by loaves or by sheeting, slitting and baking the dough followed by cooling, grinding, and drying the baked product. A golden-colored crust contributes color to the breadcrumb. The crust is obtained either by the conventional baking process itself or by toasting the bread in the dryer. Crackermeal is made from a high density dough that is sheeted and baked, then ground, dried and milled. The dough generally has a pale crust, resulting from a relative quick conventional baking process, which is carried through into the resulting crumb.
Previously in producing Japanese-style breadcrumbs, a so-called “bucket” is utilized, which forces the dough to rise essentially vertically, rather than horizontally and laterally, so as to provide a very high rise in the vertical direction with an elongated open-cell structure. The dough, after being baked in a manner to reduce the amount of crust, is then cooled to set their grain structure, and then ground and dried. In this method, conduction heating of the dough releases moisture from the dough during baking. This moisture condenses and may combine with the baking dough, resulting in hygienic and other concerns.
Alternatively for Japanese bread crumbs, the bread dough can be mixed and structured in an extruder, a continuous mixer, or a batch mixer. The resulting dough is formed to provide an elongated cell structure and then baked using a microwave oven to provide a baked product having no crust. The baked dough pieces are cooled to set the grain structure and ground into crumb. In both cases, the result is a distinctive low density crumb with no crust content. However, in the context of continuous throughput ovens, penetration of the microwaves into the dough is limited. Also, containment of the microwaves is difficult, because these ovens must have openings through which product enters and leaves the oven.
Beabien U.S. Pat. No. 2,454,370 (1948) is an early teaching of a conveyor belt system with an electronic baking oven having various types of heating including convection and heating via a high-frequency dielectric electrode to reduce the baking time, reduce oven temperatures and increase humidity dispersal in baking dough. This patent does not teach using the combination of radio frequency baking along with the convection baking with the ability to select one or more of these baking capabilities to make various types of breadcrumbs on a single production line.
Suzuki U.S. Pat. No. 5,906,764 teaches a Japanese breadcrumb production line having two conveyors running at two different speeds to stretch the dough sheet to obtain elongated cells, and then subjecting the stretched dough to a combined baking process in a single oven having both microwave and convection baking. While such a production line could possibly be used to produce both American breadcrumb and Japanese breadcrumb on the same production line, Suzuki does not teach this concept either alone or with the combined use of radio frequency baking with convection baking of dough sheets.